Time travel

Time travel is probably one of the most interesting things you can have happen in a story, but is also easily one of the most difficult to implement well, and for one very simple reason. As soon as someone can time travel, all of the events from both the past and future become questionable. Were they meant to play out the way they did, or did the time travel that was introduced in someway affect the things that set them in motion? What have the involved parties affected, and what haven't they? Is there anything that isn't touched by their actions?

I know a lot of people who absolutely love time travel in their stories, and I enjoy it, but only when it's done well. The thing about time travel is that the smallest detail can have an enormous impact on what's going on, going so far as to change the outlook of not only a single person, but an entire world, or galaxy. And it can be in ways totally unexpected, because two people falling in love who didn't before can result in a new person who may lay claim to some sort of power that redirects the course of history.

In the meanwhile, huge changes may not end up having that big of an impact. Just by eliminating one of the powerhouses that caused mayhem in history - Hitler, for example - doesn't mean that there won't be another to take his place. It's a difficult thing to determine, and it's the act of taking all of those things into consideration while telling your story that really makes it interesting.

There is also a question that exists outside of time travel that, when time travel is introduced, becomes all the more interesting to delve into - that being nature vs nurture. And you don't even have to have a definite answer for how that plays into a race as a whole. I've met plenty of people throughout my life who are far more affected by nature than nurture, and vice versa. Some people who you may have suspected to be affected by a drastic change in history may be surprisingly unchanged, and that can be an incredibly interesting path to explore. Even if what that character is comes out completely differently, that doesn't necessarily have to mean that who that character is will change as well. And, of course, vice versa.

Time travel isn't just a "correct the errors of the past" game. Attempting to correct one error may lead to five others popping up. And despite how that may sound, it's not necessarily a bad thing. Especially if the characters learn that the hard way, and have to find ways to cope with the changes that happened.

Back to the Future is an excellent example of this concept, and one that persists through the first two movies. Marty makes a mistake that causes a small change in history, and in trying to correct it, he ends up making larger changes, and then has to go back again and redo it all over, and pray that the results of that are more favorable. With each pass through history, he learns more about the consequences of his actions, and though he may not make better choices because of it, he at least tries and is more conscious of what might occur accordingly.

Dynamics are an important part of storytelling. Time travel just brings them further to the foreground.